


The Go-Between

by marysutherland



Category: Sherlock (TV)
Genre: Episode: s03e03 His Last Vow, F/M
Language: English
Status: Completed
Published: 2014-10-06
Updated: 2014-11-16
Packaged: 2018-02-20 04:37:55
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 12,795
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2415245
Author URL: https://archiveofourown.org/users/marysutherland/pseuds/marysutherland
Summary: <blockquote class="userstuff">
              <p>Sherlock has to come up with a new plan to sort out Magnussen. But he also has to solve the problem of John and Mary.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Thanks to [Kalypso](http://kalypso-v.livejournal.com/) for betaing.

Sherlock's second stay in hospital is much longer: several months, in fact. That's less about the doctors' stern warnings to him about his body needing time to recover – there's only one doctor he's ever paid any attention to – and more about the need to avoid clients. Well, one client specifically. Lady Elizabeth Smallwood.

She won't come and visit him in hospital: far too conspicuous. And nor will she risk her phone calls or letters being intercepted. But shortly after he returns to Baker Street, she will doubtless slip discreetly into the flat one evening and demand a progress report. And that will be tricky, to say the least.

Sherlock's broken bad news to clients before – your new wife's run away with her real husband, your cushy job's been set up to cover for a bank robbery  – but this is in a different league. _I attempted to negotiate with Magnussen about your husband's letters and he pissed in my fireplace. I got into his office by false pretences, but he discovered me in the act, so that he can now link you personally to an attempted cover-up. I currently have no idea on how to access the Appledore vaults and would not be fit to do so in any event. In my professional opinion, you are royally fucked and you should do whatever Magnussen demands_.

The best he can hope for at that point is Lady Smallwood taking him off the case. Even that means Sherlock loses his cover story if Mycroft or Lestrade start asking why he's still sniffing around Magnussen. Far worse is the likely consequence of the one other detail he'll have to include in his report to Lady Smallwood. _When I was in Magnussen's office someone shot me._ Magnussen may call Lady Smallwood an old woman, but Sherlock knows just how dangerous old women can be. Especially if they start asking awkward questions, like: _Who could be gunning for Magnussen, but decide to shoot you instead?_

Lestrade's being deliberately, helpfully clueless about the whole incident. Accepted Sherlock's statement that his attacker was masked, that it was all a blur and he can't remember any details about him or her. Presumably accepted whatever lies Magnussen has told in his witness statement. Lestrade will send his team off on a few wild goose chases and then let the case go cold. And why would Donovan be interested in catching someone who shot Sherlock, except to give them a medal? No problem there.

If anyone focuses properly on the case, though, they might deduce – or at least guess – that Sherlock is protecting his attacker, and that narrows down the field of suspects drastically.  And Lady Smallwood, beneath her genteel facade, is both tough and sharp. If it's clear that Sherlock can't handle Magnussen, she might try to do so herself, and Sherlock doesn't need any more unexpected female interventions.

He's fairly confident though that she won't act before she's talked to him, heard exactly what he learned from Magnussen. So he needs to stay in hospital – heroically suffering the consequences of his efforts on her behalf - until he's found a solution to the problem. Then he can make a rapid recovery, and when Lady Smallwood does come calling, reassure her that the whole situation is under control.

Well, that's the theory: now he just has to fill in the details, such as being able to leave the hospital without collapsing, and the actual taking down of Magnussen. And, of course, it’s not the only situation Sherlock has to get under control. Because the other problem – perhaps even the more urgent one – is what to do about John and Mary’s estrangement.

***   

John's making even more hospital visits the second time round. Probably worrying that, if he takes his eyes off Sherlock for too long, he'll abscond again. Mary's there frequently as well, presumably as some kind of atonement. It takes far too long for Sherlock's morphine-fuddled brain to realise that they're visiting him in shifts: he gets John or Mary but rarely John-and-Mary. And even longer to work out that the shifts are so that they avoid each other. That John can't bear even to say goodbye to Mary as she leaves; that Mary keeps looking at her watch during her visits not because she's bored, but because she's trying to work out how long she's got before John turns up.

Mary's still working at her old surgery; John's quit and got a job with an out-of-hours service. He's not cycling to work anymore, which is good, because he'd be a danger to himself in his current state of mental confusion. But he's lost weight, even with less exercise. He talks about old cases, especially the unsolved ones, as if that's going to help anchor Sherlock to life, encourage him to recover. Sherlock has a speech planned for the day John finally does want to talk about Mary – he's quite proud of how compassionate he sounds – but so far there's been no good opportunity to use it. John has to be allowed to brood for a while first.

Sherlock can at least drop a few hints. John's oddly relieved when he turns up one day to see that The Coat is back, as if it's a symbol for Sherlock's own eventual restoration.

"As good as new," Sherlock says. "Anthea knows a dry-cleaner who's exceptionally good at removing blood stains. She sends you her love, by the way."

For a moment a sentimental smile hovers on John's expressive face, and then it's gone.

"She probably doesn't remember who I am. We only met briefly," he says hastily. "And her name's not Anthea, anyhow."

All true, of course, but it's still worth reminding John about her. Because when John asked out Anthea, all he knew about her was that she had a fake name and was working for a man whom he believed to be a criminal mastermind. If Sherlock had been paying more attention when he first heard that story, he should have realised what John's type of woman was.

Looking back, he wonders how he ever missed the signs. John decided he wanted a second date with Sarah after she helped him fight Chinese gangsters, and wasn't the one with the nose some kind of mountain-climber? He remembers vaguely some unfortunate comment of his about whether she actually needed an ice-axe. As for the one with the spots, who would have thought a woman so afflicted would have had such a complex love-life?

There's another one he's missed, probably several, but there are some of John's ex-girlfriends so boring that John himself couldn't remember basic details about them. The overall pattern remains, however. It's not simply good looks that unite the women John falls hardest for: women with a taste for danger and ones with a mystery surrounding them are more prominent. It's why John's always good at chatting up witnesses in their cases.

Another image abruptly surfaces from his mind. Irene. John quite liked the thought of getting Irene's attention at first, didn't he? Yet another dangerous, mysterious woman. And then he remembers why Irene isn't a good example at all. She hurt Sherlock and John could never forgive her for that. What was it he'd said to her at the power station? _How come I can see you, and I don’t even want to?_ It hadn't simply been jealousy, had it? John can forgive injuries to himself and even people lying to him; it's the only reason their friendship’s survived four and a half years. But _enemy of Sherlock_ is an automatic red flag for John. One of the things Sherlock has to do is demonstrate to John that he doesn't have a problem with Mary. Or at least only a deductive one.

***

For the first few days Mary presumably makes the kind of banal conversation that Sherlock's brain automatically filters out. That leaves him plenty of time to contemplate getting into Appledore. Unfortunately, his first two plans both contain obvious flaws, and he can’t for the moment think of a third one. Time to distract his mind, perhaps, and leave his unconscious to solve the problem. Focus on something trivial, while waiting for inspiration. Like Mary’s knitting technique.

She’s given up talking to him by this point, and just sits by his bed and knits stuff for the baby. She is one of the more hopeless knitters that Sherlock has ever seen and he’s getting frustrated enough by it that he feels the need to explain how it should be done.

"How do you know about knitting?" she asks. "You can't have looked it up on YouTube this time."

"Mummy taught me," he replies. "She was very good. When I was thirteen, she knitted me a Möbius band scarf."

"A what?"

He explains the concept and ends up telling her quite a bit more about Mummy as the days trudge slowly past. She's a good listener, he'll give her that.

***

It’s frustrating how he’s not just tired all the time, but the drugs are also fogging his memory. He has to write things down just to organise his own thoughts, as he slowly starts to climb the mental stairs back up to where he should be. He’s not ready for Appledore, but what about Mary? If he can learn more about her, that might help him clarify what to say to John.

But he can't _ask_ Mary questions, that's the problem. She gave John the flash drive, not him, but John clearly hasn't looked at it yet. So if Mary answers Sherlock's questions, she's giving him information that John doesn't know, which is not going to turn out well. But if he deduces things about Mary himself and then checks his deductions with her, that's OK. Probably OK. He's not brilliant at ethics at the best of times, but it sounds plausible, at least.

What he can ask Mary about, he realises after some consideration, is how she broke in that night, got into Magnussen's penthouse despite all the obstacles.  It's not cheating to ask about that: John won't care _how_ Mary did it. That's not what's nagging at his mind.

But as soon as Sherlock actually concentrates, realises what the correct question is, he knows half the answer already. The next time Mary turns up, as she's just sitting down, reaching to pull out the knitting from her bag, he says:

"You had an escape route from Magnussen's penthouse via the outside of the building, so why didn't you come in that way as well, ambush him there? Why enter through his private office and risk being spotted?"

Mary straightens up, and she doesn't have the knitting needles in her hands. Which is just as well, because if you're a trained assassin, you can probably do someone a nasty injury with them. She just looks at him, with that set air to her face that reminds him she is capable of much more violence than most people he knows. But also, perhaps, of showing much more courage.

"And how does someone get past every level of security known to man and into that office?" Sherlock goes on. "By being invited through, like I was. But Janine didn't expect you that night. So who else would have let you waltz up to the top of the building?"

"Sherlock–" she begins, but she doesn't need to tell him the next bit, because he's already deduced it.

"Magnussen wanted to harass you, didn't he, so he invited you up to his penthouse?"

Her hand moves instinctively towards her phone, as if she's remembering that particular message. As if she has to check, even now, that it's been deleted.

"He said he'd had a little chat with you and John," she replies. "I thought...I thought for a moment he'd already told you what I was."

"But he didn't know you were an assassin, surely? Or he’d only have dared meet you in a public place." _Or at least in a building with your picture plastered all over it._ Even a brilliant man needs to take _some_ precautions.

"He knew Mary Morstan was dead," Mary says slowly. "That was his first message to me. Two weeks after I got engaged."

"What did it say exactly?" he asks, because strictly speaking he's still working on her case and it might help. And he knows she has an excellent memory.

" _So sorry about the tragic end of Mary Morstan. Her friends will be devastated. C. A. Magnussen_."

"That was the easiest thing to spot, for anyone who was looking," he says, knowing he should have picked it up. "Even orphans have someone around from long ago. A beloved aunt; a friend who helped look after them."

Mary nods. "Magnussen didn't mention any other deaths. And I wasn't gonna sit around and wait while he found where the bodies were buried."

It's hard to plan a murder as well as a wedding, isn't it? She'd been very efficient, making friends with Janine so quickly, but she hadn't been able to use that information. Until Magnussen finally gave her her chance.

"He doesn't expect his victims to fight back," Sherlock says. "Especially the women. That's why he liked the thought of inviting you after he'd just humiliated us. No problem in getting through the outer levels of security. But even so, they must still have checked you before letting you into the building."

He forces his mind back to that image of Mary turning to look at him that night. Don't look at the gun or her face. Dressed all in black, including black hat and gloves. Nothing too unusual there. Body armour and assault vest – bit of a giveaway. "How did you get your equipment past?"

"I had a coat on and I made sure I was looking pretty pregnant. They didn't bother searching me thoroughly, once I'd gone through the metal detector."

"And the gun?"

"I didn't take one. I knew some of the security guards were armed, so I’d be able to steal a weapon.”

Mary's voice now is calm, professional. She's been trained to make rapid decisions, hasn't she? And to fight dirty if necessary. "It was easier than I expected to start with, despite Janine saying the security was ridiculously tight. She'd told me there was another lift – for plebs – up to the top floor, as well as Magnussen's private one. I thought she meant they both went right up to the penthouse. I had an armed guard escorting me and I guessed there'd be a security camera in the lift. But I doubled up as I was coming out of it, like my stomach was hurting me. I'm short, blonde and pregnant; he didn't expect me to attack him."

Her left elbow twitches slightly, and Sherlock is abruptly reminded of Irene smoothly disarming a gunman. He nods. Also explains why the unconscious guard was up on the 32nd floor, not the 31st, where they were normally based.

"But then you realised you'd come out into his office, instead of the penthouse?" Mary had been expecting privacy, but she hadn't understood that Magnussen didn't care what his underlings saw. "And you saw Janine?"

"That was close," she says. "Magnussen must have worked out Janine and me were friends and wanted her to watch me go up to his flat. Because then she'd _know_ he had some dirt on me, and I'd know she knew that. He liked making women suffer."

He can hear the tension in her voice now. Grit in the killing machine; the personal involvement that had distorted her professional judgement.

"Janine was double-checking to make sure that Magnussen was going to stay out of the way for some time," Sherlock comments. "She didn't look round till it was too late."

"I didn't have a choice by that point," Mary says bleakly. "And I'm fast. I have to be. I've always had to be fast and good."

"Good enough to shoot my liver, thus avoiding major arteries, but not to miss the inferior vena cava. You didn't _want_ to kill me, but you knew there was a risk, didn't you?"

Mary shrugs, as if she can't explain her decision exactly even to herself. How much does your training take over automatically in such a stressful situation, Sherlock wonders, as he starts to replay the key moments in his mind. Probably some time since her last hit, but she'd have been trained to kill, not wound, wouldn't she? She could have shot him through the heart and he'd never have left that room. Or his leg, and he'd never have walked properly again. Or his hand and no more violin playing. Easy to say she made a fatal mistake, harder to know what she should have done. What he would have done if he was her? Well, not shot anyone, obviously. Not even sprained anyone.

He _thinks_ he didn't say that last bit out loud. But Mary's presumably been carrying on their conversation – her mouth's open and there's a determined look on her face - so he tunes in to her again.

"I had to shut you up," Mary says, "and you never shut up. Why didn't you let me kill Magnussen?"

"I couldn't–" he begins.

"–or let Lady Smallwood, or whoever you thought I was?"

As if it's his fault that her murder plan was unworkable. Maybe she needs to be reminded of that.

"Did you think you could possibly get away with it?" he announces, and abruptly realises that it's far harder sounding effortlessly superior when you're lying down semi-naked with a drip in your arm. "Your face was uncovered. You'd been seen going into the building, you'd have been seen going out again."

And then his mind catches up with his own words. "Oh, I see. You weren't going to leave, were you? You were going to kill Magnussen and then kill yourself."

There's a snort from Mary, as if she's in pain; but when he focuses, he realises that she's laughing. Even if she does look as if she's about to cry as well.

"Don't be bloody stupid, Sherlock," she says, at last. "I play to win. You don't like musicals, do you? Shame, because _Chicago_ 's really good. There's a song in it called 'We Both Reached for the Gun', where a woman talks her way out of a murder charge. Says she shot her boyfriend after he turned nasty when she tried to leave him."

He's going to have to ask Mary, at some point, if there's any useful crime-solving advice he could have got from going to _Les Misérables_. An irrelevant thought, which he bats away, as he concentrates on spotting the flaws in her plan. It's not the sort of plan he'd ever think of, of course...

"So you were going to claim Magnussen had invited you up to the penthouse and you'd gone to see him? And then he produced a gun and tried to rape you, but you killed him defending your honour." Ingenious, he has to admit. "But a bit difficult to explain to John why you'd gone to meet Magnussen in the first place."

"Not really," Mary says, her chin going up. "I was going to tell John that Magnussen was claiming he had information on _you_. That he’d asked me what John would do if he heard about all the things you'd got up to while you were supposed to be dead."

"That's actually quite clever." Magnussen's not the only one who understands about pressure points, it seems.

"We've all got secrets, Sherlock," Mary says, "and I'm not the only one who'd prefer John not to know the whole truth about me. Maybe you didn't do anything stupid when you were away, but that doesn't sound like you, does it?"

"What were you going to claim I'd done?" The bigger the lie, the more easily some people will fall for it. And John's pretty gullible, especially where people he loves are concerned.

"I'd say Magnussen never told me, it was all just an excuse to get me to go and see him. Because that's his idea of fun. Picking on people who can't fight back."

He's heard enough from Janine to know that’s true, that Magnussen can't resist harassing his staff, as well as everyone else.

"You wouldn't have got away with it," he tells her, but his voice doesn't sound convincing.

"I've known people get away with murder before now," Mary says, and he wonders if John ever told her about Jefferson Hope. Probably not murder on John's part, but certainly homicide.

How could he not have seen what was happening, before he got shot? He had seen it, hadn't he, but too late? Or rather smelt it. You don't wear perfume if you're breaking into a building, not if you're a professional. But you do wear it if you're trying to act like a harmless woman. John had thought of Mary automatically with the perfume, but why hadn't he _seen_ Mary?

"How did you avoid John when you went downstairs after the shooting?" he demands.

"I didn't go back down," Mary says. "I knew there had to be a fire-escape somewhere in the penthouse and I found it. Setting off alarms didn't matter by that point; Magnussen had all the evidence he needed against me already.”

"The alarms just stopped; it all went quiet. Or maybe I couldn't hear them anymore." All he could hear had been Moriarty singing. Moriarty singing nursery rhymes about him dying. Mary's saying something and for a moment he can't hear it, because he has to delete Moriarty singing nursery rhymes first.

He shakes his head, trying to focus. "What did you say?"

"I don’t know _why_ it took John so long to find you,” Mary repeats. “I thought he'd be right up the stairs behind you, that I had no time to explain."

"He told me afterwards he was trying to check if any of the security cameras let him see into the penthouse; he didn't want to rush up the stairs blind into an ambush."

John for once doing the sensible thing and it had almost killed Sherlock. No, he'd almost got himself killed. Thought Mary wouldn't be able to pull the trigger, thought he could just walk over and take the gun from her, take control of the situation in the way he always did. That was really why she'd shot him, wasn't it? Because no-one likes a smart-arse. His human error. She'd asked him twice where John was, and he hadn't picked that up. If he'd only realised that that was what was scaring her, not the thought of shooting someone. That he'd removed her only means of escape, cornered her.

He closes his eyes, trying to puzzle out what the right thing is to say to a cornered assassin whom you're trying to help. When he opens them again later – two hours later? – Mary is gone.


	2. Chapter 2

**Summary for the Chapter:**

> Sherlock's learned some more about Mary from talking to her; now he needs to start making _deductions_.

John's mood is increasingly filthy towards the end of the month and Sherlock can't immediately work out why. Until he finally does some calculations and realises the likely issue.

"So how did the twenty-week scan go?" he asks, and John's hands clench till his knuckles go white.

"I didn’t go, “John says sulkily. “I don't even know whether it's my child."

Sherlock's natural reaction is just to roll his eyes, but he suspects that won't be enough this time. Someone has to talk some sense into John and it seems, unfortunately, that it will have to be him.

"Prenatal paternity tests are possible," he points out. "Slight risk to the foetus, of course, but if you think it's not yours..."

"Of course, I wouldn't...I wouldn't put Mary through that." The same priorities as that last night in Baker Street: _My lying wife_. And only then: _The woman who’s carrying my child_. Mary first, the child second.  John'll doubtless be an adequate father, but you don't marry a forty-year old woman if you're desperate for a family. It's Mary who matters to John, it always has been. Sherlock just has to remind him of that, help him see her again.

"And really, John," he says, "you have no reason to suspect that she has been unfaithful, especially given her obvious devotion to you." He had hoped that John would have learned something from the parade of adulterers traipsing through 221B over the years, but obviously his mind's still clouded.

"Devotion? You call that devotion?"

"She was ready to kill a man to protect her marriage. You may think she showed extraordinarily poor judgement, but it certainly doesn't suggest shallow emotions. None of the other obvious symptoms of clinical psychopathy either. No lack of remorse, and the CIA wouldn't have taken her on if she'd had early behavioural problems."

As he expects, mention of the CIA gets John's attention again. John can normally cope with facts slightly better than with his own emotions, and he asks, clearing his throat: "Mary's working for them?"

"Was working for them. She's clearly not doing so anymore."

"Because the CIA never goes round London terrorising people? I must tell Mrs Hudson that," John says, with what he probably considers devastating sarcasm. There's nothing like pointing out the flaws in someone else's arguments to cheer you up temporarily, as Sherlock knows very well.

"No, Mary was doubtless doing similar things and worse during her time with the CIA. But you saw how the Americans operated in the Adler case: a team comes in for an operation and then leaves. The CIA wouldn't _need_ Mary to go undercover in Britain for five years, and if for any reason they did, they'd have made a more professional job of setting her up. Provided someone from her early life to confirm who she was. Whereas what we have here is a freelance effort, albeit by someone who knew roughly how to carry it out."

"So we can be fairly confident she's an ex-spook from somewhere, at least?" John says and Sherlock watches an idea slowly dawn. "I know you thought she wasn't English, but could she be ex- _British_ intelligence?"

"She'd have been a fool to stay in London if she was. And especially to invite my brother to her wedding reception."

"Yeah, I suppose so. So what _was_ Mycroft doing all the time I was engaged to a killer?"

That's actually bothering Sherlock as well, but it's a problem for a later date.

"You'll have to ask him. I suspect as usual he's up to some particularly devious game, and doesn't mind about the collateral damage."

"Not the only one," John says, and how does he stop John's mind hammering away and hurting himself like this? Give him a case, that's all he can do. The case of his own wife.

"Do you want to know how I deduced that Mary used to work for the CIA? And what else I've deduced about her?" he demands, and John's reply is immediate.

"OK, we'll do it your way. How did you deduce that?"

"She was brought up in both Britain and the US. Her English accent is flawless, and she uses British childhood slang unselfconsciously, like 'bogs' for toilet. On the other hand, shooting a tossed coin is a quintessentially American trick, almost certainly learnt in childhood. I wasn't sure whether you'd be more impressed by Mary's skill or horrified by her carelessness about gun safety."

"Bit of both, really," John says automatically, and then shakes his head in frustration.

Possibly even aroused, Sherlock thinks. At some point in the future, he will have to get both Mary and John along to a rifle range, because it's going to be hilarious to see who'll win and how exactly John will react if he loses. But right now, John needs to focus on facts about Mary, so he can possibly forget at least some of his nightmares about her.

"Her accent is working class and southern," Sherlock goes on. "Her familiarity with guns from an early age suggests most likely to be from a rural red state area in the US. Neither is the kind of background where you'd move easily between continents, under normal circumstances. But there is one obvious possibility: that one or both parents were with the US Air Force."

"You mean that they were stationed over here during some of her childhood?"

"It's a working hypothesis, at least. If she went to school here, at least for a while, she'd have adapted her accent very quickly. It'd also be far less risky coming up with a plausible back story for herself if she knows the British education system well. And there's no obvious gaps in her knowledge of early eighties trivia, I presume?"

"Not really, no." John's picturing Mary in his mind, now, trying to remember her. Seeing her as a human being, however flawed, not just a cardboard cut-out with a label marked ‘killer’ round her neck. Keep that going.

"One other hint that might fit with her being a service brat," Sherlock goes on. "She comes to London knowing no-one five years ago, yet she's soon got a wide circle of friends. Used to having to make friends quickly, possibly suggests she moved around a lot during her childhood."

John nods her head. "She's a lot more positive towards soldiers than your average _Guardian_ reader. Quite happy for me to invite Major Sholto along to the wedding and no snide comments about war criminals." His left hand clenches again. "But then I suppose that'd have been a bit hypocritical even for her. She hasn't just worked for the CIA, has she? She said life imprisonment for what she'd done. That means something pretty serious after she'd left them, some reason they wouldn't protect her."

Sherlock has to agree. He's on thin ice now, but he has to keep the deductions coming, because his brain is starting to rev up and some of what he says, at least, is almost sure to be right. He's thinking clearly about Mary at last, putting the evidence together, and the words start to form in front of his eyes. Unfortunately, there are some aspects he can't soften. _Here's hoping there isn't one too many deduction this time_ , he thinks as he opens his mouth again:

"There are a number of crimes for which you can get life imprisonment, but there’s one that comes immediately to mind. Mandatory life sentence for murder in the UK; possible death penalty in the US. And she'd been trained to assassinate people during her time at the CIA."

"Great. I married a contract killer. It'll look good in _Hello_ magazine, won't it?"

John's gallows humour never fails him, but suddenly Sherlock can see the way forward.

"She could have killed one person or she could have killed fifty: life imprisonment either way. But that's not the important point right now."

"It's not?"

"No, it's _when_ she killed them. When she became Mary Morstan five years ago, was she doing that to hide her previous identity as a killer or in order to establish an identity in which she could continue to kill?"

"We can't know." John's voice is bleak.

"We can make some deductions, surely. She wasn't carrying out killings in London," Sherlock says, because he's already rechecked his memory files for those. "And there's not a lot of demand for hired gunmen outside the M25. The lucrative jobs are mostly overseas. Besides, there's the fact that she's a nurse."

John mutters something indistinct about Harold Shipman being a doctor.

"The point is, John, she would have to train, or at least retrain as a nurse in the UK. Someone would have spotted if she was unfamiliar with NHS procedures, wouldn't they?"

"She told me she'd worked as a shop assistant for years," John says quietly. "She got to her mid-thirties, decided she had to do something more with her life and came to London, to Guy's."

A woman trying to reinvent herself: a plausible story. And more or less true if you substitute 'assassin' for 'shop assistant'.   

"Several years training, then working as a practice nurse. Doesn't leave much time for overseas trips to carry out hit jobs, does it?"

"She was working part-time," John says, and then bites his lip, because even he can see that doesn't change the equation substantially.

"The overwhelming balance of probability, therefore," Sherlock goes on, "is that Mary was on the run for her crimes before she came to London. For the past five years, she has not been working as an assassin, but instead trying to hide herself away and build a new life. Unfortunately, there is no statute of limitations for murder."

"So Mary killed someone back in the US?" John sounds calmer. "Or at least when she was based there?"

Do long-ago murders count less? Maybe if you want to believe that someone can change. But Sherlock can’t allow too much wishful thinking by John.

"One person or possibly more," Sherlock says. He concentrates, trying to work out times, probabilities. The CIA would probably have recruited Mary out of college, so mid-1990s, but unlikely to be employed by them for assassinations in her early years. So active period perhaps around 2000 onwards. On the run by 2008. What was happening in America then? Anything to make Mary want to leave? 

He shakes his head. Too wide a timeframe to give useful information. Mary could have had time for dozens of freelance killings, before she decided to retire, but no way of telling. _Oh_ , but there might be. Don't think about time. Think about retirement funds.

"Mary came to London in 2008," Sherlock says. "She'd need money to set up her new identity."

"London's not cheap either," John replies with feeling. "And if the CIA's like the army, she wouldn't have had much of a pension. Even if she didn't leave in disgrace."

"So how did she raise the money?"

"Killing people. She's a killer, remember?"

"Not cheap to hire a contract killer either," he says. "Even allowing for expenses, you'd make a decent profit from each job."

"So?"

"So where's Mary's money if she'd made a long-term career out of it?"

"Stashed away in some Swiss bank account!" John retorts without hesitation.

"The wedding put you both in debt. Mary's an orphan; well, she claimed to be. Perfectly easy when you started living together for her to say, _Oh, I inherited something when my parents died_ or _This is the insurance payment from the car crash_. Follow the money, John. Either she was a hopeless bargainer, or she doesn't have much money because she didn't kill many people."

"Or she's a spendthrift?"

John's instinct for ridiculous hypotheses is kicking in yet again. Why can't he see the evidence?

"Mary's not a spendthrift, and she's certainly not a hopeless bargainer. You know how much she got the catering for the reception knocked down."

John scrambles to his feet, starts to pace around the room. "So that's proof that she hasn't killed many people, is it? That we got a good deal on our wedding?"

Sherlock waits as John thinks about punching the wall, doesn't (because he knows it upsets the nurses), finally remembers to breathe and very slowly turns round to look at Sherlock. Waiting for him to say something, because John clearly can't manage a coherent sentence.

"If you want proof of what Mary's done," Sherlock says, as gently as he can, "you read the files she gave you. If you want logical deductions, you ask me."

"So what do you talk to her about, when she's here?" John asks in frustration, his anger automatically rechanneling itself into a different direction.

"Knitting. And musicals, sometimes."

"And what does she...?" John begins and then he stops, running his fingers up and down his neck. Trying to be the reasonable man he likes to imagine he is.

"Don't ask me what she thinks. I've been wrong about her before," Sherlock says, because he's not up to that responsibility.

"Not as wrong as I was," John says wearily. "I...why did you say that I knew what she was? I didn't see anything."

"No, _you_ wouldn’t. That was the point," Sherlock says, because he's been blind too. "Last November, your life was being threatened, and Mary and I came to rescue you. I didn't think a car was fast enough, so I stopped a motorbike. Your fiancée got on as a pillion passenger, without bothering to enquire whether I actually had a driving licence, and proceeded to hang on uncomplainingly while I went rather spectacularly off-road. She then helped me drag you out of a bonfire where someone was attempting to incinerate you."

"Yeah, she told me about the bike ride. Sounded pretty hairy." John's almost smiling now.

Sherlock's starting to feel the need for another morphine dose, but he keeps going, pushing the words out and hoping that John's slow mind can catch them.

"Did at you any point suggest that she should not undertake such rides in the future?"

 "I couldn't tell Mary that. She'd have kill–" John bites off the word, and Sherlock hurries on, because he may not have much longer for anything to register.

"And did she do anything more the next day to warn _you_ off further adventures? Apart, presumably, from cracking a rather tasteless joke about how hot you were. Moving swiftly along. Ten months later, your pregnant wife accompanied you to a crack den, and then went off on her own with a junky and a drug dealer, because _you_ needed to sort out your best friend's own drug problems. Does that sound like the action of a responsible father-to-be?"

"I couldn't just let you–"

"But you could just let _her_. John, if you thought Mary was an ordinary, commonplace woman, you have treated her with appalling disregard, and let me do so too. We treated her the way we did because we knew she could cope with it. You may not have known it consciously, but the evidence was there for us both to see."

He can hear the emotion in his own voice. He can't keep calm, detached, not when John's pain is even greater than his. He wonders if he should offer some of his morphine to John.

"It's your job to see the bloody evidence, it's not mine!" John yells. "Why didn't you see it?"

Nothing left but the truth now. "Because you wanted to be with her and I wasn't going to stand in the way of that. I knew she was a liar, but I also know that you don't stop loving people just because they're liars."

John blinks and ducks his head and then walks out of the room. And that's the problem, of course. John deep down still wants to be with Mary. That's why he hasn't read her files: because it's hard enough for him to cope with what he already knows about her. But he also hasn't simply walked out on her. Easy enough to move back to Baker Street and make polite statements about how he'll help with the baby when it's born, but the marriage is over. Everyone would assume he'd finally realised he was gay, but John can surely live with that?

John's staying with Mary even though he's furious with her. Can't even bear to speak to her. Only one logical deduction to draw. But John's logical thoughts take a long time to surface from the entanglement of his emotions, and there's no easy way to short-circuit the process.

Eventually, John's mind is going to have to accept what he's already instinctively decided. For the moment, all Sherlock can do is rest, before he goes back to trying to work out the central problem.  How to get into Appledore and remove the threat to both Mary and Lady Smallwood.

***

What he ideally needs, Sherlock decides, is an inside man or woman. Vicky the maid, perhaps, who once dated a ghost? _She_ wouldn’t be scared of what Magnussen might find out about her personal life. But it’d take months to install her or someone else in Appledore and he’s not sure how long he’s got. Quicker to suborn one of the staff already there; should be perfectly feasible once he knows all about them.  
He can’t send John down to Hampshire – far too conspicuous – but he has Billy Wiggins and Langdale Pike and a string of other anonymous figures who drift into the hospital to take orders and bring back reports. Invariably, disappointing reports. Magnussen’s chosen his staff with great care. Janine may have been able to break from him – or did Magnussen let her go? – but none of the others would dare swap sides. Years in jail or worse for any subordinate who dared let Sherlock into Magnussen’s lair. He needs another approach.

***

What would Mycroft do? Not a question Sherlock ever likes posing, but necessary on this occasion. And he’s picked up a lot about his brother’s more dubious methods over the years. But in this case, Mycroft too would be stymied; Magnussen’s too important a man for his brother’s normal tactics to work. Mycroft could spirit Jim Moriarty off to an underground dungeon for weeks, but Magnussen would be missed. Compromising secrets found on Magnussen’s computer? Hard to pin on Magnussen personally and his newspapers would fight back. God knows there are enough embarrassing stories about the secret service to discover, and Magnussen’s bound to have found out some of them. Mycroft can hardly risk having the Bruce-Partington Programme or Operation Coventry appearing on all the front pages, can he?

So Mycroft’s no use, and Sherlock certainly can’t talk to Lestrade about his plans. But John can’t think straight about Magnussen at the moment, when he’s still obsessing about Mary. Maybe if Sherlock can work out a few more deductions about her, John’ll be of use again. Be back to being the sounding board, the conductor of light that Sherlock needs to solve the whole case. If he can just solve the problem of Mary, that’s the first step.


	3. Chapter 3

**Summary for the Chapter:**

> Sherlock's still having problems figuring out Mary Watson and Appledore

Another talk with Mary will probably allow some more deductions, but Sherlock has to wait, plan their next conversation correctly. Till he's sure he's observed Mary enough to know all her tells, confirmed at least some of his hypotheses about her past. Till he's feeling strong enough to lead the conversation where it needs to go. It’s just possible that the CIA have traced Mary to London and are using her again – not a likely hypothesis, but they do intrude on Mycroft's patch sometimes – and if so, she's hardly going to admit it easily.

"You read the _Guardian_ ," he says to her when she comes in one blustery autumn afternoon. Early morning shift at the surgery, baby kicking her a lot – he's slightly surprised John's child hasn't tried to head-butt her yet – but someone gave her a seat on the tube and that's almost restored her faith in humanity.

"Yeah," she says. "Not a terribly difficult deduction, that one, when I'm carrying a copy." She's almost back to her old manner with him now, treating him like some odd combination of friend and child. 'Mary Morstan' isn't a facade in that sense; there's no major difference in personality, not like with 'Rich Brook' and Moriarty.

"Why do you read it?" he asks.

"Because I like knowing who the Prime Minister is," she says cheerfully. She's good at putting on a brave face on a hopeless situation; must have helped her survive when she first came to London. "And if I put on the TV news, John starts yelling at it if people say something stupid. Dunno where he gets that from."

"Why the _Guardian_ specifically?"

"Well, I wasn't gonna read one of Magnussen's papers, was I? Even before I knew about him, he came across as pretty slimy."

"There are other newspapers. And the fact that you regularly buy that one and don't just read it on your phone suggests a certain loyalty."

"Yeah, I've been reading it for years."

"How many years?"

"I dunno. Five, six, seven, maybe. Can't really remember." She's puzzled now, but not yet suspicious.

"But why would a former CIA assassin read a paper like that? One that makes clear its opposition to US foreign policy? Not very patriotic of you."

"I–"

"The _Guardian_ website had an upsurge in readership in the US during the War on Terror, didn't it? People who wanted a different view of the world. So did you become a _Guardian_ reader because you were disillusioned with the CIA or disillusioned with the CIA because you were a _Guardian_ reader?"

He watches her smile fade as she realises what he's up to.

"It doesn't matter, Sherlock," she says quietly. "None of it matters anymore."

"Because you _were_ disillusioned with the CIA, weren't you? You'd killed too many people, killed the wrong people. You told us what you were that night. _People like Magnussen should be killed. That's why there are people like me._ You didn't try and claim to be a field agent, someone who only fought in self-defence. You outed yourself as a killer when you didn't need to."

When she doesn't smile she looks her age, the lines on her face those of a woman who's felt more than her normal share of emotions.

"I am a killer," she says at last. "I've made a lot of excuses for what I did, but I can't make them anymore." 

"You left the CIA. You'd decided you wanted to help people, not hurt them, and you chose a job where being organised and unsqueamish was an advantage. But why didn't you simply retrain as a nurse in the US?"

She shrugs. "The Agency would have come back to me. If they think you're useful, they won't let you go for good. You can always be _persuaded_ to do just one more job. And I couldn't live with AGRA any longer, I knew I couldn't."

She'd have a better story than that if she _was_ working for them again, he thinks.   

"So what does an ex-assassin do?" he asks. "It can't have been cheap getting a false passport to travel to the UK. Putting things in place to create your new identity."

He waits for her excuses or for to her to confirm his deduction of _not many_. But she just looks at him and gives a brief, fake smile.

"It didn't seem any worse than the things I'd done in the Agency," she replies. "And it doesn't actually matter to most people _why_ they're dead. Whether they deserved to be killed or not. Well, except to you, obviously. You had to come back to life, just so you could solve your own murder."

If they're going to get anywhere, he has to admit his mistake the night he found her.

"I was wrong about why you didn't kill Magnussen, wasn't I?" Sherlock says. "It wasn't fear that John might be a suspect; no-one would seriously have believed that he tried to kill me _and_ Magnussen. One or the other, but not both."

She doesn't try to protest that John would never kill anyone; she knows her husband that well, at least.

"When I got up to the penthouse, you had Magnussen on his knees, but he was still talking, wasn't he?" Sherlock goes on. "He’d explained already that if you murdered him, your past would come out, hadn’t he? He asked if you were going to kill us both: he wouldn’t say that unless he knew by then that he was safe. You'd planned his murder well, Mary, but you hadn't planned what would happen afterwards, had you? Lady Smallwood might believe her husband's letters were in London, but you should have known better. You should have known about Appledore."

"Of course I knew about Appledore," Mary replies promptly, and it's as if they're back in the penthouse again, having the conversation they should have had if they both hadn't been so startled. "That wasn't the problem about me killing him. It was having Janine out cold downstairs. I was trying to work out if I could somehow buy her off, get her to say that Magnussen had attacked her as well."

"Your plan was going wrong already, and now you had an extra complication. Your one chance at that point was persuading me to keep quiet, but you didn't think you had any time left. And then I called you 'Mrs Watson'. That was my final mistake, wasn't it?" He'd thought at the time it would reassure her and it had nearly got him killed.

He watches Mary blink back tears from her eyes. "Showed where your loyalties lay. That I'd been stupid to imagine you'd ever help me without telling John."

"You thought of doing that? Of having me take your case?"

"I wouldn't have put it like that, but yeah. But I had to get rid of Magnussen first. You may hate the man, but you wouldn't kill him and you wouldn't have let me or John shoot him. And he had to die, Sherlock, he really did. Only way it could be done."

Mary's not talking about Magnussen deserving to die, as she'd told John. She's operating on the strategic level now, which saves Sherlock's time. So what was her plan? And is there any chance she might still be hoping to kill Magnussen?

"What was your next step after his death?" Sherlock asks.

"I’d told a friend of mine to take a letter round to you at Baker Street. For you and only you to read."

Sherlock’s now back at the crime scene as it should have been. With his visit to the CAM building deleted – which means he can’t get shot – and Mary being whisked up in a lift directly to Magnussen’s penthouse. In the office below, therefore, there is no John, and Janine has been sitting peacefully all evening, doubtless daydreaming of her boyfriend, until she hears a shot. And in the penthouse itself, there's a security guard who's been knocked out and had his gun taken. As well as Magnussen lying dead and a small pregnant blonde next to him who says she shot him with his own gun, because she was scared of what he was about to do. Signs of a struggle between the two of them.

The evidence might not entirely hang together, of course. Not to an expert eye, but she's only got to fool the Met, hasn't she? The white supremacist guard isn't going to admit he was taken down by a _girl_. He's going to say that Magnussen asked for his gun and then knocked him out. Or some other half-witted lie that will muddy the waters. Testimony from Magnussen's former staff about his crudeness. His invasion of personal space, fingering women, licking them. The jury are going to be glad a man like that is dead, not care too much about how.

What about the bits that don't add up? Mary's body armour, in case Magnussen did have a gun on him – American presumptions coming out there – three possible ways of disposing of that, he'll have to explore those later on. The marks on the floor where Magnussen knelt –  Mary was scaring the fight out of him, presumably, so that when she had to get in close for the kill shot he'd be too stunned to react. Other slips that she would inevitably have made and Sherlock would inevitably have spotted. Unless he'd been told not to.

"You did want to hire me, didn't you?" he says. "But not as a consulting detective.  More a consulting obfuscator. To explain away clues, not find them."

She mutters something about _razzle-dazzle_ , but he's not listening. Because there's a second image in his mind now. Him sitting in an ambulance, a shock blanket round him, though not in shock that time, telling Lestrade:  _you’re looking for a crack shot, but not just a marksman; a fighter. His hands couldn’t have shaken at all, so clearly he’s acclimatised to violence_. He'd also deduced John had strong moral principles, but you can't get everything right.

He'd have covered for her with the police, wouldn't he, once he'd worked it out? But not with John, he couldn't have kept it from John. Whatever pathetic story she'd spun to him.

"What were you going to tell me in the letter?" he asks harshly, because she isn't John and she isn't him, and he's not sure how much more generosity she deserves.

"I was gonna give you the flash drive. Tell you to read it, so you'd know what to look for in Magnussen's files."

She was going to tell him the truth about herself? But that's ridiculous, for several different reasons.

"That makes no sense," he protests. "If you thought I could break into Appledore, you had no need to shoot Magnussen."

"Appledore's impregnable. I knew no-one could get in there. I couldn't and nor could you."

"Exactly. There's no use in killing Magnussen if you haven't cracked Appledore already. He must have told you that himself. If he's murdered, the vaults containing his evidence will be opened by the police, looking for suspects."

She nods her head, obviously still not getting the point.

"The police, not the Security Service," he goes on impatiently. "No point in expecting me to intercede with Mycroft, even if I could. His men would have to stay well away from any criminal investigation of Magnussen: there must be no suspicion of a cover-up. The police would read Magnussen's files. All his files. Did you not think about that?"

"Of course I did," she says and her grey eyes fix onto his. "But you work with the police, don't you? And there'd be hundreds of files for them to sort out. Are you really telling me you couldn't have nicked one file from a police station before they got round to looking it at properly?" Her mouth broadens into a smile. "John said you regularly used to pinch George Lestrade's warrant card."

"It's Greg Lestrade," he barks out, and for a moment her smile is triumphant.

"I told John you did know his name, really." She draws a breath and goes on, serious now. "It was risky, but it was the only way to do it. I couldn't get into Appledore, so I had to get the files out of it somehow. That's the problem."

"And the police were your solution."

"Yeah. Once Magnussen's dead, they go in there with a search warrant and just bring everything out. All the security systems in the world don't matter once the mind behind them's gone."

"That was your plan?" It's at once banal and wonderful, and surely he should have spotted her talent for lateral thinking during the wedding preparations? "No proof, I suppose?"

She sighs. "Sherlock, why do you _think_ I had a flash drive with the details about who I really was on me? It’s not the sort of thing I'd hang onto after I became Mary Morstan, is it? Think I'd _want_ to keep reminders of who I used to be?"

"You kept your equipment." He consider briefly. "But then I suppose John kept his gun. Highly illegal, of course."

"Tools of the trade," she replies. "Hard to let go of your protection. John's got other souvenirs from his army days as well. But then he doesn't have to be ashamed of what he did. I do."

So much data that he'd missed that evening, but then he had been haemorrhaging at the time. He's not in shock anymore; he needs to use his mind properly today.

"You said the files on your drive were originally intended for me, not for John.  That implies that you created them relatively recently, since I returned. When did you do that?"

"Just before the wedding. I knew I was gonna have to kill Magnussen. That's why I got so friendly with Janine, to try and find out about his routine. His favourite restaurants, his routes to the office, that kind of thing. But it took time; I didn't dare discuss him too much, in case she got suspicious."

Yet another advantage in being eccentric: Janine didn't wonder about _Sherlock's_ peculiar questions to her.

"I thought maybe I could promise to show her some pictures from the honeymoon when I got back," Mary goes on. "Get up to her office that way, work out how to get in from outside, while I was still in a fit state to climb. But she was too busy with her new _boyfriend_ to return my calls."

The wedding, then the pregnancy. Two obstacles that she'd tried to use for her benefit. All fits with what he knows of her, of course. Opportunistic, good at thinking on her feet, manipulative, but not a pathological liar. An odd sentimental streak and surprisingly honest at times. Perhaps it's not a coincidence that she and Janine hit it off.

He mustn't let sentiment blunt _his_ mind anymore. He'd been mostly right about what she was, once he'd thought clearly, but he needs to double-check she's telling the truth now.

"When exactly did you create the files?" he asks. 

"You know that day I sent you out to find a case, while I stayed at Baker Street? I used John's laptop when I was compiling the data. No-one's gonna wonder why Sherlock Holmes is looking up the details of a murder in 2007 or a CIA operation from 1998. I deleted it all off the hard drive afterwards, obviously. John's got the only copy now."

She must realise he can check those statements, if he needs to do so. Though if she is lying, he can probably crack her story open right now: elaborate lies almost always contain some flaw that a logical mind can spot. Sherlock props himself up a little more securely in the bed, somehow restrains himself from turning the collar of his pyjama jacket up, and says,

"You were going to slip the flash drive to me after the wedding service, were you, as a little thank-you for the best man?"

"I told you," Mary replies wearily. "I was going to give it to you after I killed Magnussen."

"Once you knew I'd survived the shooting, you could have given it to me then."

"In the hospital?" she protests. "You said _Mary_. The first thing you said when you woke up. The first thing you said to _John_."

"You needed to get me alone," he says. "You were looking for me with a gun in your pocket as well as the flash drive. Bit of a mixed message there."

"I feel safer with a gun," she says, and that probably is the truth. Sherlock wonders whether she wakes up sweating sometimes, knowing that if she _had_ shot at him at Leinster Gardens, she'd have killed her husband instead. He still worries about that sometimes; he doesn't know if John's ever worked it out. Or maybe John would have preferred that to happen, which is a terrible thought.

"You didn't ask for my help even then, did you?" he says. She’d only said _What do you want?_ and that could mean anything.

"No point. I knew by then you weren’t on my side."

"You'd been trying to get me on _your side_ , hadn't you? Went out of the way to be friendly to me. You didn't think it was enough to count on my _chivalry_?" She's not Irene; she didn't try to use sex to manipulate him. She used friendship and that's a far more dangerous coin.

"I was counting on the fact that you love John and so do I. That you'd decide Mary Morstan was worth saving. I knew the minute you came back to England that you were gonna work out who I was eventually. I wanted to try and make you like me before that happened."

Her plans are simple; that doesn't mean they can't work.

"So that I could help you lie to John?" He can't help anger creep into his voice, and she smiles at him, shaking her head.

"Oh Sherlock, don't give me that. You spent two whole years lying to him. You lie to John over and over again. You always have done, you always will do. It's just that, eventually, he always catches up with you."

"And he's caught up with _you_ now."

Mary's smile abruptly vanishes and her head sinks into her hands.

"Magnussen has as well," she says. "I'm going to drag all three of you down, aren't I? How do you want to appear in his newspapers, Sherlock? As the great detective who didn’t spot his best friend was marrying a murderess? Or the man who knew and let him marry her anyway?"

It's not what the headlines say about _him_ that bothers Sherlock. Not after Rich Brook, not after Janine. It's John who's in danger. Sherlock's only vulnerable to pressure because of John's connection to Mary, but _why_ does Magnussen need him to be vulnerable?

Something that Mary's just said. _Drag all three of you down_. A slip of the tongue, obviously; she meant _Drag all three of us down_. But suppose she _is_ dragging three other people with her, not just himself and John? Because Magnussen's messages started before the wedding, before Lady Smallwood became his client, didn't they? This is something bigger than them, has always been been. And then he spots the metaphorical elephant in the room.

"It's not John that Magnussen's after," he announces. "It's not even me. It's Mycroft. Give Magnussen a lever long enough and he can move the world. You lead to John and John leads to me and I lead to Mycroft."

"Oh _fuck_ ," Mary says, and she sits there, frowning down at herself, and he waits to see if she can somehow be a conductor of light to him the way John is. Because her mind isn't anything like his own and that's the point, isn't it?

"Only one option left then, isn't there?" she says, looking up at last, and there's a resigned set to her face that he recognises now. Another bloody soldier going nobly to her death. "You help me fake my death."

"What?"

"You know how to do that," she says and she gestures to her stomach. "I'd prefer not jumping off a building at the moment if you could avoid it, though."

"You were willing to ki...do serious damage to me to stay with John and now you're just going to run away?" It doesn't make sense.

"It's got too big, hasn't it? Magnussen won't leave this one alone. You might help me, but Mycroft definitely won't. It's going to come out, be in all the papers. And I don't want the baby born in prison."

All three of you. Not Mycroft as the third piece of collateral damage, but John and Mary's child. Suddenly he can see it; he _is_ their child, age six or seven. And round him is the ring of other children, jeering: _Your mother's a murderer_. Not that. He can't let that happen.

"John would come with you, after we’d faked your death," he says. "I'd make him."

She shakes her head. "He can't forgive me. At least this way I can tell my daughter some story about her dead war-hero father, and she can imagine he loved me."

"He _has_ to forgive you. For his own sake."

"How? He can't hit me and he can't talk to me. It takes facing certain death to get John willing to talk about his feelings." She shrugs. "Maybe that's how it should end. Not a fake death after all. Us two storming Appledore together, all guns blazing. Die like heroes. We might even be able to take out Magnussen as well."

For a horrible moment he can actually see it, or at least the aftermath. Lestrade on the terrace of Appledore, saying gruffly: _John must have tried to cause a diversion, but he didn't know about the tripwire_. _It'd have been quick, at least._

"No!" he shouts and then he stops. Lestrade is there in his mind because it's a crime scene, and that’s who you get at crime scenes. The police. Which is who they want to be there, isn't it? That was Mary's plan all along. But they need a different crime. 

"No," he says, because Mary can't help him now. "You don't have to die. And nor does Magnussen. Go. I need to think."

He doesn't know what her reply is, because he's already trying to work out how to get an invitation to Appledore.


	4. Chapter 4

**Summary for the Chapter:**

> All that remains for Sherlock to do is get out of hospital and into Appledore

It's not getting into Appledore that's the problem, Sherlock decides. Magnussen will invite them in, just to play games with them. It's getting out again safely that's the problem. He spends days scribbling plans, constraints, scenarios down. Puts in _POLICE_ and then crosses it out. He can steal one file, but what about all Magnussen's other victims? Lord Smallwood may deserve to be charged, but there are doubtless other people who ought not to be. He writes down _INTELLIGENCE_ instead and then adds, reluctantly, beneath: _a.k.a. MYCROFT_. He needs to double-check that he's right about the back-up copies.

"Pity the Appledore vaults don't have a self-destruct mechanism, like Irene's phone," he says and a familiar voice beside him replies:

"What?"

When he looks up he realises John has been sitting at his bedside for at least an hour.

"Busy?" John asks, putting his book away.

"Working out what to do next."

John smiles. "I'd say getting out of hospital would be the ideal move. Preferably before Christmas."

There are advantages to John's limited mind sometimes. He's not paralysed by the thought of Magnussen, is he? Just focusing on the immediate problem.

"It's nearly Christmas?" Sherlock asks, because it's hard to keep track of time when every day is the same.

"It's November the sodding 20th and they've put tinsel up already."

Sherlock had wondered about that, actually.

"Why do I need to be out of hospital by Christmas?" he asks.

John grimaces. "I've worked in hospitals at Christmas. The staff always make a special effort to cheer the patients up."

"Oh god. Right, Operation Christmas Escape starts here. Though if I get out I'll be dragged off to my parents for a celebratory family event."

"And what's so wrong with that? I've met your parents. They're nice people."

John's _asking_ for retaliation, isn't he?

"John, you told me your parents were living overseas and that was why you never saw them–"

"And?"

"And it turns out that they had retired to the Isle of Wight. They came to the wedding and I don't think you said more than twenty words to them all day. And eight of those were 'Glad to hear the ferries were running OK.' "

John bites his lip. "It's not...it's not that we don't get on, just we have absolutely nothing to say to one another. When I give them my excuse each year about how I won't be able to make it home for Christmas this time, I can practically hear the relief over the phone.”

Sherlock has to admit, the phrases _John Watson_ and _Isle of Wight_ don't sit easily together. "So what are you planning to do?"

John shrugs. "If you're still in here, kidnap you for the day and we'll find somewhere to go."

"And if I've escaped before then?"

"Dunno." His face creases in thought. "I suppose I'd been thinking this year I'd just be at home with Mary, but..."

There's something different in his voice when he speaks of Mary this time. Oh, of course, sentiment.  
It shouldn't make any difference to how you feel about your deceitful wife whether it's Christmas or any other time of the year, but it does to most people. Sherlock remembers that with Lestrade.

He can't do without John. It's impossible. And John can't delete Mary, doesn't want to. So Sherlock’s going to have to say something, isn't he? Give John the push towards the solution that he has already unconsciously decided on.

"John, you want to be with Mary," he announces. "It's time to stop this dragging on. You have to tell her you forgive her, because you obviously do. And preferably in time for you to ask her what she wants for a Christmas present, so you don't get her anything as terrible as last year's necklace."

As expected, John's immediate focus is the irrelevant details, giving Sherlock's main message time to sink in.

"She said she liked that necklace," he protests.

"Yes, after a pause of at least eight seconds after unwrapping it. And when you've asked since then when she's going to wear it, she's probably told you she's saving it for a special occasion or she's meaning to buy an outfit it'll go with."

"She doesn't like the necklace I got her," John replies unhappily. "Even though she said she did."

Reminding John that Mary doesn't always tell him the truth possibly isn't Sherlock’s best tactic, is it? He hurriedly adds:

"Yes, but to be fair, you didn't like it either, did you? Clearly you just got it at the last moment because you'd gone shopping for lingerie, hadn't remembered what Mary's bra size was and couldn't deduce it."

"Don't...just _don't_ tell me you are able to deduce my wife's bra size," John says, and Sherlock gives him one of _those_ looks, and suddenly they're both laughing, almost unstoppably.

"What I probably can deduce," Sherlock says eventually, "it what Mary would like as a present this year, so you can leave things almost to the last moment, if really necessary. But you do have to say something to her."

"I don't know what to say." John's retreating to the practical difficulties now, which is a good sign.

"Then you need to sit down and work it out, in writing if necessary. For all our sakes.” He's just about to say, _You should ask Lestrade for some tips: he's good at writing speeches_ , when he remembers that John may not want Lestrade to know he's married to a former assassin.

Though it’s a shame they can't get anyone else involved. However much he may dislike Christmas cheer, some kind of event to be organised is just the kind of thing to help the reconciliation. A few moments of privacy to stumble through heartfelt phrases, and then the distraction of other things to do, so you don't have to keep on talking to one another. His mother's ability to remember that the potatoes need peeling or the milk jug scrubbing has saved many an awkward but necessary emotional encounter from complete meltdown.

His mother. Of course. Christmas, sentiment, Mycroft – can't moan about associating with assassins, can he, probably has his own stashed away somewhere – happy marriages, decreased security, probably a skeleton staff even at a country residence.

John is staring at him, so Sherlock hands him a few sheets of blank paper.

"Right. You need to work out what to say to Mary and I need to work out how to give my big brother poison for Christmas. Though not a fatal dose, unfortunately."

***

Sherlock knows how to make it work now. Not just how to get into Appledore, but how to deal with the vaults. But he has to take John with him this time; he can't leave him behind again. Sherlock can't save Mary and everyone else and not let John help him do it. Which means he also has to get Mary out of the way.

"I've got a plan to get into Appledore," he tells her, as she sinks wearily down in the chair beside his bed. "But it's potentially dangerous."

"Who for?" she asks, which shows the right priorities.

"John and myself, mainly. But also possibly for you and the" – he mustn't say foetus – "baby."

She thinks for a moment, unconsciously fiddling with her wedding ring. Then she smiles ruefully at Sherlock. "We've not got any better options, have we? And it's John's baby."

"I never doubted that," he replies in surprise.

"And mine. The poor thing hasn't got a chance. She's bound to take stupid risks, it's in her genes. What do you need me to do?"

"I can't tell you the details yet, I need to talk to someone first. But I hope John and I are going to Appledore after Christmas. I'm sorry, I may be going to get your husband killed." He knows _he_ shouldn't be smiling at this point, and finds that he is anyhow.

"Like John _needs_ help doing that," Mary replies, smiling back. "I can't stop him, and I won't stop you." She pauses and then adds, more slowly: "Just promise me one thing, Sherlock. Don't get John put in prison. Because if you did–"

"You'd never forgive me."

"You'd never forgive yourself. How long do you think John would last in prison?"

He's literally never thought of that. Not even when he and John were sharing a cell together. Admittedly he wasn't up to much thinking at that point...

"I've always presumed it would not be that much worse than boarding school," he says hastily and then remembers that John went to a comprehensive.

"And you thought you could escape, didn't you?" Mary says, and her smile is brittle now. "Come on, Sherlock, I bet you read POW stories as a kid. First thing you gonna do is start digging a tunnel."

"A little too Count of Monte Cristo. I was planning riots instead. John was in the army, he could survive."

She nods. "For a while, yes. A fixed term sentence, he'd have the discipline to keep going. A life sentence, though, no way out ever...it'd break him, wouldn't it?”

She understands John, doesn't she? Almost as well as he does, sometimes. And now she's looking at him, waiting for his response...

"Oh," he says. "You're expecting some tactless joke from me about marriage also being a life sentence, aren't you?"

"Pretty much," she says, and he suddenly has to ask her the one question he doesn't know the answer to.

"You said you wanted me to like you, so that I'd be willing to help you. But why do you like _me_?"

She smiles at him as if he's the stupid one. "Because John loves you and you make him happy. What's not to like about that? In small doses, obviously."

One small stray piece of the puzzle clicks into the pattern.

"You weren't deliberately ensuring that John stayed away from Baker Street?"

"Course not. I told John we ought to come and see you, but he said he was too busy doing up the flat. He got obsessed with getting things ready for the baby over the summer. Once it sunk in properly that he was really gonna be a father, he was terrified, so he started trying to organise everything, just like you...never mind. But it was a good job you distracted him with your drug-taking.”

Typical John. Decides to do what he thinks someone normal would do and drives himself round the twist attempting it.

"I promise I won't get him imprisoned when we go to Appledore," Sherlock says. "If the worst comes to the worst, I'll say he's my hostage."

Mary gives him a hard stare. "The police aren't gonna fall for that again, are they?"

"Probably not. In that case I'll say that I didn't tell him what I was planning, that I was keeping him in the dark all the time."

"Yeah, they'll probably believe that."

"But in that case," he says, "I can't tell you what's going to happen either, Mary, any of it. I can't let you know things that I don't tell John. So are you ready for whatever may happen?"

She's silent for a few moments and Sherlock follows her gaze as she thinks. Lingering on her wedding ring – the risks to John. Followed by an instinctive glance down at her swollen body – what's best for the baby? And then he sees her eyes travel, almost unwillingly, towards himself. Not his face, but the right side of his chest. The blue pyjama jacket currently hiding the scars of the hole she made in him. She stares as that and he watches the emotions play over her face, now the mask is finally removed – guilt, anger, determination, hope. And then she raises her gaze to meet his and says:

"I guess all three of us are just going to have to trust you, Sherlock."


End file.
